regarding about export of neptune data

I am trying to export Neptune RDF data using the following tools.

amazon-neptune-tools/neptune-export at master · awslabs/amazon-neptune-tools https://github.com/awslabs/amazon-neptune-tools/tree/master/neptune-export

But, Error occurs.

Error

[ec2-user@bastin neptune-export]$ sh ./bin/neptune-export.sh export-rdf -e neptestdb-cluster.cluster-xxxxxx.ap-northeast-1.neptune.amazonaws.com -d /home/ec2-user/output
Creating statement files

Completed export-rdf in 1 seconds
An error occurred while exporting from Neptune:
java.lang.RuntimeException: java.lang.NullPointerException
    at com.amazonaws.services.neptune.rdf.NeptuneSparqlClient.executeQuery(NeptuneSparqlClient.java:166)
    at com.amazonaws.services.neptune.rdf.io.ExportRdfGraphJob.execute(ExportRdfGraphJob.java:31)
    at com.amazonaws.services.neptune.ExportRdfGraph.run(ExportRdfGraph.java:55)
    at com.amazonaws.services.neptune.NeptuneExportCli.main(NeptuneExportCli.java:54)
Caused by: java.lang.NullPointerException
    at com.amazonaws.services.neptune.rdf.io.EnhancedTurtleWriter.handleStatement(EnhancedTurtleWriter.java:42)
    at com.amazonaws.services.neptune.rdf.NeptuneSparqlClient$2.handleSolution(NeptuneSparqlClient.java:161)
    at org.eclipse.rdf4j.query.resultio.binary.BinaryQueryResultParser.parse(BinaryQueryResultParser.java:192)
    at org.eclipse.rdf4j.query.resultio.AbstractTupleQueryResultParser.parseQueryResult(AbstractTupleQueryResultParser.java:48)
    at org.eclipse.rdf4j.http.client.SPARQLProtocolSession.getTupleQueryResult(SPARQLProtocolSession.java:693)
    at org.eclipse.rdf4j.http.client.SPARQLProtocolSession.sendTupleQuery(SPARQLProtocolSession.java:372)
    at org.eclipse.rdf4j.repository.sparql.query.SPARQLTupleQuery.evaluate(SPARQLTupleQuery.java:55)
    at com.amazonaws.services.neptune.rdf.NeptuneSparqlClient.executeQuery(NeptuneSparqlClient.java:126)
    ... 3 more
[ec2-user@bastin neptune-export]$

The procedure is as follows.

Command

1. download tool

git clone https://github.com/awslabs/amazon-neptune-tools.git

2. install mvn for build

sudo wget http://repos.fedorapeople.org/repos/dchen/apache-maven/epel-apache-maven.repo -O /etc/yum.repos.d/epel-apache-maven.repo
sudo sed -i s/\$releasever/6/g /etc/yum.repos.d/epel-apache-maven.repo
sudo yum install -y apache-maven
mvn --version

3. execute build

cd /home/ec2-user/amazon-neptune-tools/neptune-export
mvn clean install

4. exexute neptune-export.sh
cd /home/ec2-user/amazon-neptune-tools/neptune-export
sh ./bin/neptune-export.sh export-rdf -e https://neptestdb-cluster.cluster-xxxxxxx.ap-northeast-1.neptune.amazonaws.com -d /home/ec2-user/output

If you have any idea, please contact us. thank you for your cooperation.

Solution

Thanks for reporting this. I've identified the problem and will push an update to the repository later today or tomorrow. In the meantime, you can replace line 42 in EnhancedTutleWriter.java with the following:

Resource context = statement.getContext();
if (context != null){
    prefixes.parse(context.stringValue(), this);
}